Thanks to the protection and anonymity it provides, using a proxy server is the most convenient way for scraping public data online. However, managing proxy servers may consume more time than the web data extraction itself, so it’s crucial to learn how to do it properly before you begin working on your next web scraping project.
What is a proxy?
Before getting into the definition of a proxy server, it’s essential to understand what IP addresses are and how they work. An IP – short for Internet Protocol – address is a unique string of numbers that identifies any device connected to the internet. Consisting of four numbers separated by dots, IP addresses typically look something like this: 188.8.131.52.
IP addresses are necessary for devices or servers to communicate with one another. For example, if you search for “best SEO software,” your IP will send a request to the search engine’s server. Then, using your IP address, the search engine will find an answer and return it.
Meanwhile, proxy servers work as relays between your device and the websites you’re visiting. When you enter a website while connected to a proxy, your traffic is routed through their server. So, your original IP address is masked and replaced with the IP of the proxy server.
The IP assigned by your ISP (short for Internet Service Provider) is a static IP address, so web servers see the exact string of numbers every time you go online. However, by connecting to proxy servers and hiding your IP, web crawling or scraping can be done in privacy and on a large scale.
Why choose proxies for scraping?
Using a proxy server isn’t the only way to scrape the web; but due to the many benefits it comes with, it’s considered the most reliable one. Let’s take a closer look at some of the said benefits of a proxy server:
- Reliability. To prevent web scrapers from making too many requests, websites set limits to the amount of data you can gather. As a result, your spider can get banned or blocked. With a pool of proxies, you can bypass the limit and send multiple requests from different IP addresses.
- Access to geo-focused data. As a marketing or sales tactic, websites (especially online retailers) display content differently depending on the visitor’s physical location or device. With a proxy server, you can bypass these restrictions and change the location of your IP. It’ll look like you’re making a request from a different area, allowing you to scrape public data from anywhere in the world.
- Increased data volume. Although it’s not possible to tell if a website is being scraped, it is possible to detect suspicious scraper activity. For example, if your scraper doesn’t browse the web irrationally – as a human would – or you access the website multiple days in a row at the exact same time, it’s easier to detect and ban you. Meanwhile, a proxy server allows you to make unlimited concurrent sessions to one or multiple websites.
- Boosted security. Finally, by hiding your device’s IP address, a proxy server provides an additional layer of security and anonymity.
Is using proxies legal?
When it comes to web scraping, “Is it legal?” is a question that often arises. In fact, the legality of web scraping is a much-debated topic in the data community.
In their simplest form, using proxies and scraping public data are neither illegal in themselves. However, there are quite a few nuances to that statement – there are dozens of specific illegal web scraping examples.
For instance, you can still get in trouble if you use a proxy server to scrape copyrighted data. That said, before starting to work on your web scraping project, you should seek professional legal advice regarding your specific situation.
Different proxy types explained
There are multiple proxy types to choose from, each one with its unique pros and cons. Due to the amount of information on proxy types online, it may be difficult to choose the best option for your use case. Let’s take a look at the three most common types of proxies – residential, datacenter, and mobile – along with their features.
Residential proxies use the IP of physical devices from actual households. Since residential IPs are real IP addresses assigned by Internet Providers, they allow you to easily replicate organic user behavior. Hiding behind a real IP address minimizes the risk of being detected, receiving CAPTCHAs, or getting banned.
Residential proxies have sub-genre proxies, and they’re called rotating proxies. While scraping, the IP address of a rotating proxy will regularly change, so it’s harder for anti-bots to detect and ban them.
A residential proxy using an actual IP address is one of their greatest advantages; on the flip side, they’re pretty costly since they’re hard to obtain. In some cases, residential IPs can be an overkill since you can achieve the same result with a different proxy type without breaking the bank.
Another common solution for web scraping is using datacenter proxies, which use IPs housed in data centers.
A single server can host numerous datacenter proxies, and they’ll have the same IP subnetwork, for example: 184.108.40.206, 220.127.116.11, and 18.104.22.168.
In other words, any batch of these proxies will look alike, increasing the risk of getting banned while web scraping. However, it can be prevented by choosing a trustworthy proxy service provider that supplies private proxies.
On the positive side, a datacenter proxy is quite fast, so it’s a great choice if you want to complete your project quickly. Also, they’re much cheaper than residential ones, so if you’re on a budget, they’re the way to go.
The principle of mobile proxies is similar to the residential proxies – they utilize IP addresses assigned to private mobile devices provided by MNOs – Mobile Network Operators. Mobile IPs direct their users’ requests through mobile devices connected to cellular networks.
As you may have guessed, mobile IPS are, too, difficult to obtain, so they tend to be more pricey. Long story short, mobile IPs are the best bet when you need to scrape mobile web results exclusively.
Bear in mind that the three proxy types we just went over can also be split into three categories according to their access kind – you can use a public, semi-dedicated, or a dedicated server.
Managing a proxy pool: challenges and solutions
Choosing the right type of proxies for web scraping and finding a reputable provider is essential. However, it doesn’t end there; to avoid getting banned, you need a pool of proxies and a proxy manager tool.
If you tried scraping with a singular third-party proxy, the end result would be similar to using your own IP address – the risk of getting detected would increase, the geo-targeting options would shrink, and so on. That said, you need to build a pool and use proxy management software that splits the traffic over a large number of proxies.
Proxy pool size
Let’s talk about the size of your proxy pool, aka, the number of proxy IP addresses needed for your web scraping project. The proxy pool size is impacted by various factors, such as your chosen proxy type or the number of requests you’ll be submitting per hour.
The sophistication of your target website(s) should also be taken into account – scraping a large website that employs anti-bot measures will require a bigger proxy pool. Finally, the size of the pool will depend on how complex your proxy management system is, whether you have session management and proxy rotation set up.
Now let’s take a look at the most common difficulties your proxy management software may run into and the solutions to them.
- Errors. If your proxies run into technical issues – timeouts, bans, or errors – the pool should automatically switch to a different IP and retry the request.
- Ban identification. There are different types of technical difficulties you may encounter while web scraping, including CAPTCHAs, redirects, and blocks. Hence, your proxy solution should be able to identify the experienced issue – only this way, you’ll be able to troubleshoot and correct it.
- Delay randomization. Applying throttling and randomizing delays will help to conceal the web scraping activity, decreasing the chance of being detected.
- Geo-based targeting. In your proxy pool, you should have IPs based in different locations in case you’d need to scrape geo-restricted data.
- User-Agent management. User-agent is a string of text for web servers to identify a user’s device, operating system, and browser. Changing the string regularly – also known as practicing string spoofing – will minimize the possibility of being detected.
- Session control. By implementing rotating sessions, you’ll be able to mimic organic behavior and, once again, reduce the ban risk.
Managing a pool of a few proxies is easy; however, if it’s hundreds or thousands of proxies, it can get difficult quickly. By using a proxy manager and combining the tactics mentioned above, you’ll be able to prevent CAPTCHAs, IP bans, or other technical issues, making web crawling and scraping effortless.